U.S. Pat. No. 6,198,995 generally relates to a method after a vehicle has entered a sleep mode, the disclosed method places the vehicle monitoring system into longer and longer nap periods provided the monitoring system does not receive a wake-up signal from one of a plurality of vehicle subsystems. During the nap periods, the monitoring system requires a reduced amount of operating power thereby decreasing the parasitic current drain on the battery during the sleep mode.
U.S. Pat. No. 8,285,039 discloses a system, method and device for monitoring a vehicle that is provided wherein a vehicle monitoring device regulates its power consumption of a host power source based upon determined states of operation of the vehicle. The power consumption management scheme of the monitoring device utilizes the following modes of operation to regulate power consumption: a work mode, a transport mode, and sleep mode, and a deep sleep mode. The mode of operation of the monitoring device depends on the determined state of vehicle operation. The monitoring device utilizes the various states of operation to power down certain portions of the monitoring device in order to reduce the electric power consumed by the monitoring device. A communication network is adapted to communicate the vehicle data to an end user via an access device. The communication network is also adapted to communicate end-user data via an access device to the monitoring system. The power consumption management scheme of the monitoring device may be remotely configurable by the end user in order to customize the monitoring device's utilization of the stored energy resident within the host power source.
WO3011/003813 generally relates to a method for operating a control device (1) for controlling a plurality of functions in a motor vehicle, wherein a number of functions are performed in a normal operating mode, wherein the control device (1) is connected to a number of waking sources (4), having the following steps:—taking on (S3, S4) a first sleep operating mode, if a first condition is present in the normal operating mode, wherein only part of the functions are performed in the first sleep operating mode and/or at least one of the functions is operated at reduced performance, so that the overall energy consumption in the first sleep operating mode is reduced relative to the energy consumption in the normal operating mode;—taking on (S5, S6) a second sleep operating mode if a second condition is present in the first sleep operating mode, wherein only part of the functions are performed in the second sleep operating mode and/or at least one of the functions is operated at reduced performance, so that the overall energy consumption in the second sleep operating mode is reduced relative to the energy consumption in the first sleep operating mode.